GCN Circular 45924
Subject
Konus-Wind detection of GRB 261011A
Event
Date
2026-10-12T15:15:46Z (a day ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A. Ridnaia, D. Frederiks, A. Lysenko, V. Panteleeva,
D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long-duration GRB 261011A
(SVOM detection: Huang et al., GCN 45895;
Swift detection: Cenko et al., GCN 45896)
was detected by Konus-Wind (KW) in the waiting mode
at about T0 = T0 (SVOM) = 49747 s UT (13:49:07).
A Bayesian block analysis of the KW waiting mode data
in the 20-400 keV band reveals a ~20 sigma count rate
increase in the interval from T0+1.7 s to T0+66.468 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB261011A/
The total burst fluence is 1.30(-0.21,+0.62)x10^-5 erg/cm^2,
and the 2.944 s peak energy flux, measured from T0+10.532 s,
is 4.63(-4.27,+4.74)x10^-7 erg/cm^2/s.
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst,
measured from T0+1.7 s to T0+66.468 s,
can be described by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.8(-0.1,+0.2) and Ep = 198(-67,+869) keV.
All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.